⚠ CriticalFine silken webbing linking leaf axils and stems — a definitive marker of established Tetranychus urticae colony activity; inspect undersides of stippled leaves for mite colonies.
Spider Mite Infestation — Tetranychus urticae
Commonly affects: Most indoor tropical foliage, particularly Ficus lyrata, Alocasia, Dracaena, Orchids
Fine, stippled yellow or bronze speckling appears on upper leaf surfaces as mites pierce individual cells to feed. Infestations progress to visible webbing beneath leaves and between stems, giving a dusty, silken appearance. Severely affected leaves turn bronze-brown and desiccate. Spider mites thrive in hot, dry conditions and reproduce extremely rapidly — a single female can lay 300 eggs over her lifespan.
Potential Causes
- 1Low humidity (below 40%) and warm temperatures (above 26°C) creating ideal mite breeding conditions
- 2Plants stressed by drought, nutrient deficiency, or root problems becoming more susceptible
- 3Introduction of infested plants or cut flowers nearby without quarantine
- 4Dusty leaf surfaces enabling mites to move and anchor without disturbance
Solution Steps
- 1Isolate the affected plant immediately from all other houseplants to prevent spread.
- 2Take the plant to a sink or shower and spray every surface — top and underside of leaves, stems, and soil surface — with a strong stream of lukewarm water. This mechanically removes up to 80% of mites.
- 3Prepare a neem oil spray: 5 ml cold-pressed neem oil, 2 ml castile soap, 1 litre warm water. Shake vigorously and apply to all leaf surfaces, including undersides.
- 4Repeat the neem oil treatment every 3 days for three cycles to break the egg-to-adult lifecycle (approximately 7–10 days at 25°C).
- 5Increase ambient humidity to 60%+ — spider mites cannot reproduce effectively above 70% RH.
- 6Introduce predatory mites (Phytoseiulus persimilis) as biological control for severe infestations.
Prevention Tip
Wipe leaf surfaces monthly with a damp microfibre cloth to remove dust and disrupt mite colonies before they establish. Regular misting or a nearby humidifier maintains the humidity level that deters spider mites.
Related Issues to Explore
Powdery Mildew — Erysiphe & Golovinomyces spp.
Both spider mites and powdery mildew thrive in warm, dry conditions — treating one without improving humidity often allows the other to follow.
Read guide
Bacterial & Fungal Leaf Spot — Xanthomonas & Cercospora spp.
Mite stippling and bacterial spots both damage leaf surfaces — confirm the cause by checking for webbing (mites) vs. water-soaked halos (bacterial).
Read guide
Etiolation — Leggy, Weak Growth from Insufficient Light
Light-stressed plants are significantly more susceptible to mite infestation — correcting the light environment reduces stress and pest pressure simultaneously.
Read guide
